Patent GB-763526-A (GB)
Title: Improvements in or relating to sheet feeders
Inventor: MESTRE LUIS
IPC: B65H7/06
Filed: 1954-08-20
Abstract: 763,526. Feeding sheets. GESTETNER Ltd. Aug. 20, 1954 [Oct. 12, 1953], No. 24335/54. Class 100(1) Sheet separators:- In apparatus for successively removing sheets from the top of a pile the suction or other separator moves the sheets from the pile to feed rolls or other receiving means from where they are conveyed over a pivotally mounted ejector plate which is tilted, against the action of a spring, by a detector member to deflect the sheets downwards into a delivery shoot if two or more superposed sheets have been separated from the pile, the ejector plate being restored to normal position by means actuated by the tilting operation. As shown, each sheet 26 is separated from a pile 25 by two suction fingers 32 and placed on a feed roll 33, Figs. 7 and 12, which, in co-operation with a narrow upper roll 131, feeds the sheet between a second feed roll 35 and co-operating balls 250 held in cages 251. Normally, the sheet is then fed over an ejector plate 37 to an endless band conveyer 38. Each suction finger 32 is clamped in a block 125 adjustable along a rod 126 rotatably carried in the upper ends of arms 128 secured to a shaft 113 which is rocked by a cam 59. The movements of the rocking arms 128 are controlled by a stationary, cam 134 with which engages a follower 132 on an arm 133 secured to the rod 126. Flexible air tubes 134a connect the suckers 32 to a transverse header tube 134b, Fig. 7, which is connected through flexible tubing to an air-pump 136, Fig. 1, driven by a motor 137. There are two valves in series in the flexible pipe line, one being actuated automatically through a lostmotion linkage from the rocking shaft 113 to control the air supply to the suckers 32, and the other being manually-operated by a handle 180, Fig. 3, to enable the air flow to be established by the pump before sheet feeding commences. Sheet-separation is facilitated by air jets from other flexible tubes leading from the same pump 136. A central front and two side jets are provided, the latter being provided by nozzles adjustably carried by a shaft 169. Fig. 7. The sheet-feeding apparatus is driven from a printing- machine by chain and sprocket gearing which is geared to the conveyer 38, feed rolls 33, 35, and a cam shaft 56. Pile tables:-The pile 25 is carried by a support 27 having rollers 28 which engage parallel rails 29, attached to chains 30 which pass upwardly over sprockets 62, around sprockets 63, and then extend downwardly and carry weights 66. Rolls 65 hold the chains around the sprockets 63 which are secured to a shaft 64 adapted to be driven periodically under the control of a feeder 31, Fig. 7, to raise the support 27 and keep the top of the pile at a constant level. A gear 70, secured to the shaft 64, meshes with a pinion 71 secured to a rachet-wheel 72 engaged by a pawl 78, Fig. 3, on a carrier 74 which is adapted to be rocked by a cam 58. Both the pawl 73, and a holding pawl 84, can be held away from the rachet-wheel by a hand-lever 93 to enable the pile support 27 to be moved up and down by means of a hand-wheel 109, 110. A shoulder on the pawl carrier 74 co-operated with a pivoted hooked pawl 99 so that the carrier can-. not be rocked by the cam 58 until the feeler bar 31, and. an arm 104 movable therewith, cause the release of the pawl 99. The feeler and arm are lifted periodically by linkages operated by a cam 57 against the action of a spring. The top sheets of the pile 25 are guided at the front, back, and two sides. A central block 185, Fig. 7, adjustably secured to the cross shaft 169 is combined with a yoke 187, adapted to be pivoted upwardly about the shaft 169, carrying a rod 190 having a collar 192 thereon which supports a pair of pivoted fingers 197 engaging the back of the pile. Fingers 200, Fig. 1, carried by rods 201 mounted on adjustable slides on the shaft 169, engage the sides of the pile. A member 210, Fig. 3, has near its top edge two metal strips 212, Fig. 7, which engage the front edge of the pile, and associated with each strip is a spring scraper finger 218 against which each top sheet 26 is forced past to ensure that two sheets are not lifted simultaneously. The support 27 itself is provided with adjustable members 223 to accommodate different widths of sheets. Faulty-feed direction &c.:-The device which detects the separation of two or more superposed sheets from the pile by the suckers 32 comprises a member 34 mounted on a stud 266, Fig. 12, eccentrically mounted in a frame member 254 such that the distance of the stud from the top of the feed roll 33 can be varied by adjusting a nut 259. The member 254 is connected to two frame members 242 mounted on the header air-tube 134b, Fig. 7, a parallel rotary shaft 240, and a parallel fixed shaft 241. The roll 131 is carried by arms 244 pivoted to the frames 242,. and can be swung away from the roll 33 and held in that position by a plunger 246 having a bayonet slot co-operating with a pin 247. When two superposed sheets pass between the detector 34 and roll 33, the detector is raised due to its eccentric mounting, and partially rotated against the action of a spring 269 to release a latch 274 which is fast with an arm 275 connected by a link 276 to the upper arm of a lever 277, Fig. 3, secured to shaft 41 which is adapted to be rocked by a cam 59. On this release, a spring 284 pulls back the link 276, rocks the shaft 41 counterclockwise to bring a follower into contact with the cam 59 which then acts to rock the shaft 41 clockwise and restore the latch 274 into engagement with the detector 34. The ejector plate 37, over which the superposed sheets are fed, is secured to the shaft 41 so that these sheets are diverted into a shoot 42 on the initial rocking of that shaft. Specification 763,527 is referred to.